Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE

Superradiative decay and enhanced optical nonlinearity of low-dimensional excitons

Eiichi Hanamura

Published Aug 1, 1990• 7 citations
Publisher

Abstract

We want to make the best use of the mesoscopic or macroscopic transition dipolemornent of excitons by controling the size and dimension of the materials. First, the semiconductor microcrystallites embedded in insulators or glasses are shown to have the mesoscopic transition dipolemoment of excitons1 . As a result, the exciton in CuC1 microcrystallite with the radius 80 A superradiatively decays in 100 pico-second2. Futhermore, the exciton-exciton interaction and the decay and relaxation of the exciton work effectively in deviating the excitons in the microcrystallite from ideal bosons and this system shows the large third-order optical susceptibility"3 of an order of iO esu when we assume the 0.1% packing of the CuC1 microcrystallites. These predictions have been confirmed expriment ally4'5. Second, the two-dimensional excitons in quantum wells can superradiatively decay in the direction perpendicular to the surfaces2 . This brings about the quick response and the deviation of the excitons from ideal bosons at the same time. The latter effect as well as the two-dimensional macroscopic enhancement of the exction transition dipolemoment enhance the third-order optical susceptibility3. Both the superradiative decay rate and increase as does the coherent length, which is inversely proportional to the square root of the exciton line width6.

DOI
10.1117/12.20326

Related papers

Superradiative decay and enhanced optical nonlinearity of low-dimensional excitons

Eiichi Hanamura

We want to make the best use of the mesoscopic or macroscopic transition dipolemornent of excitons by controling the size and dimension of the materials. First, the semiconductor microcrystallites embedded in insulators or glasses are shown to have the mesoscopic transition dipolemoment of excitons1 . As a result, the exciton in CuC1 microcrystallite with the radius 80 A superradiatively decays in 100 pico-second2. Futhermore, the exciton-exciton interaction and the decay and relaxation of the exciton work effectively in deviating the excitons in the microcrystallite from ideal bosons and this system shows the large third-order optical susceptibility3 of an order of iO esu when we assume the 0.1% packing of the CuC1 microcrystallites. These predictions have been confirmed expriment ally4'5. Second, the two-dimensional excitons in quantum wells can superradiatively decay in the direction perpendicular to the surfaces2 . This brings about the quick response and the deviation of the excitons from ideal bosons at the same time. The latter effect as well as the two-dimensional macroscopic enhancement of the exction transition dipolemoment enhance the third-order optical susceptibility3. Both the superradiative decay rate and increase as does the coherent length, which is inversely proportional to the square root of the exciton line width6.© (1990) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Jan 1, 1990•0 citations

Superradiative Decay and Enhanced Optical Nonlinearity of Excitons in Qunatum Wells

E. Hanamura

We evaluate the exciton coherence length and discuss theoretically how it determines its superradiative decay time and its third-order optical nonlinearity in the qunatum wells and microcrystallites.

Nonlinear Optical Properties of Materials•Jan 1, 1988•0 citations

Wannier exciton superradiance in a quantum-well microcavity

Gunnar G. Bjork, Stanley Pau, Joseph M. Jacobson +1 more

Excitonic superradiance has been predicted to induce a rapid decay rate of coherently excited excitons in thin quantum wells and microspheres. In this paper we revisit this problem and derive the enhancement factor of the radiative decay due to superradiant effects. In a GaAs quantum well, the excitonic superradiant radiative decay can be roughly 320 times faster than the decay of a free electron-hole pair. The exciton decay rate depends strongly on the lateral size of the wave function when the size is smaller than the inverse of the wave vector of the emitted light. In a GaAs quantum well this corresponds to a distance of \ensuremath{\approxeq}365 \AA{}. Therefore, it is predicted that localization and elastic phonon scattering may lead to decay rates substantially smaller than that predicted for an ideal quantum well. It is also shown that if the quantum well is placed inside a microcavity, the decay rate can be enhanced even further since the cavity modifies the available density of radiation states in a way that matches the superradiant emission. It is predicted that in a matched dielectric cavity the decay rate can be enhanced by an additional factor of 100, but that inhomogeneous broadening may in practice limit the possible enhancement.

Physical review. B, Condensed matter•Dec 15, 1994•63 citations

Excitonic nonlinear optical responses

Eiichi Hanamura

The enhancement of /spl chi//sup (3)/(-/spl omega/;/spl omega/,-/spl omega/,/spl omega/) and switching rate has been confirmed under resonant pumping of coherent excitons. We propose theoretically the following nonlinear optical responses of the exciton: (1) Superradiance of Frenkel excitons and excitonic n-strings; (2) Frenkel and Wannier excitons show different characteristics of the third-order optical responses /spl chi//sup (3)/(-/spl omega/;/spl omega/,-/spl omega/,/spl omega/); (3) Generation of phase-conjugated wave shows singular spectrum near mobility edge of the exciton in a bulk crystal.>

IEEE Lasers and Electro-Optics Society Annual Meeting (LEOS)•Dec 30, 2002•0 citations

Enhanced optical nonlinearities in quantum boxes: theory and applications

Juan Francisco Lam

Current interest in the optical behavior of semiconductor microcrystallites or boxes stems from their potential use in optical signal processing operations. Understanding of the fundamental mechanisms1-3 as well as the limitations to optical devices4,5 is still being considered actively. This paper reports the results of our studies of the nonlinear optics of excitons confined to zero dimension and examines its manifestation on the phenomena of dynamic Stark effect, optical phase conjugation, and two-beam coupling.

Conference on Lasers and Electro-Optics•Apr 25, 1988•0 citations

Mechanism for enhanced optical nonlinearities and bistability by combined dielectric–electronic confinement in semiconductor microcrystallites

D. S. Chemla, David A. B. Miller

We propose a new type of mechanism for enhanced optical nonlinearities and intrinsic optical bistability that relies on the combination of intrinsic feedback due to local field effects and excitonic resonances in semiconductor crystallites. These effects will be further enhanced by quantum confinement in small crystallites.

Optics Letters•Aug 1, 1986•106 citations
We want to make the best use of the mesoscopic or macroscopic transition dipolemornent of excitons by controling the size and dimension of the materials. First, the semiconductor microcrystallites embedded in insulators or glasses are shown to have the mesoscopic transition dipolemoment of excitons1 . As a result, the exciton in CuC1 microcrystallite with the radius 80 A superradiatively decays in 100 pico-second2. Futhermore, the exciton-exciton interaction and the decay and relaxation of the exciton work effectively in deviating the excitons in the microcrystallite from ideal bosons and this system shows the large third-order optical susceptibility"3 of an order of iO esu when we assume the 0.1% packing of the CuC1 microcrystallites. These predictions have been confirmed expriment ally4'5. Second, the two-dimensional excitons in quantum wells can superradiatively decay in the direction perpendicular to the surfaces2 . This brings about the quick response and the deviation of the excitons from ideal bosons at the same time. The latter effect as well as the two-dimensional macroscopic enhancement of the exction transition dipolemoment enhance the third-order optical susceptibility3. Both the superradiative decay rate and increase as does the coherent length, which is inversely proportional to the square root of the exciton line width6.
We want to make the best use of the mesoscopic or macroscopic transition dipolemornent of excitons by controling the size and dimension of the materials. First, the semiconductor microcrystallites embedded in insulators or glasses are shown to have the mesoscopic transition dipolemoment of excitons1 . As a result, the exciton in CuC1 microcrystallite with the radius 80 A superradiatively decays in 100 pico-second2. Futhermore, the exciton-exciton interaction and the decay and relaxation of the exciton work effectively in deviating the excitons in the microcrystallite from ideal bosons and this system shows the large third-order optical susceptibility3 of an order of iO esu when we assume the 0.1% packing of the CuC1 microcrystallites. These predictions have been confirmed expriment ally4'5. Second, the two-dimensional excitons in quantum wells can superradiatively decay in the direction perpendicular to the surfaces2 . This brings about the quick response and the deviation of the excitons from ideal bosons at the same time. The latter effect as well as the two-dimensional macroscopic enhancement of the exction transition dipolemoment enhance the third-order optical susceptibility3. Both the superradiative decay rate and increase as does the coherent length, which is inversely proportional to the square root of the exciton line width6.© (1990) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Excitonic superradiance has been predicted to induce a rapid decay rate of coherently excited excitons in thin quantum wells and microspheres. In this paper we revisit this problem and derive the enhancement factor of the radiative decay due to superradiant effects. In a GaAs quantum well, the excitonic superradiant radiative decay can be roughly 320 times faster than the decay of a free electron-hole pair. The exciton decay rate depends strongly on the lateral size of the wave function when the size is smaller than the inverse of the wave vector of the emitted light. In a GaAs quantum well this corresponds to a distance of \ensuremath{\approxeq}365 \AA{}. Therefore, it is predicted that localization and elastic phonon scattering may lead to decay rates substantially smaller than that predicted for an ideal quantum well. It is also shown that if the quantum well is placed inside a microcavity, the decay rate can be enhanced even further since the cavity modifies the available density of radiation states in a way that matches the superradiant emission. It is predicted that in a matched dielectric cavity the decay rate can be enhanced by an additional factor of 100, but that inhomogeneous broadening may in practice limit the possible enhancement.
The enhancement of /spl chi//sup (3)/(-/spl omega/;/spl omega/,-/spl omega/,/spl omega/) and switching rate has been confirmed under resonant pumping of coherent excitons. We propose theoretically the following nonlinear optical responses of the exciton: (1) Superradiance of Frenkel excitons and excitonic n-strings; (2) Frenkel and Wannier excitons show different characteristics of the third-order optical responses /spl chi//sup (3)/(-/spl omega/;/spl omega/,-/spl omega/,/spl omega/); (3) Generation of phase-conjugated wave shows singular spectrum near mobility edge of the exciton in a bulk crystal.>
Current interest in the optical behavior of semiconductor microcrystallites or boxes stems from their potential use in optical signal processing operations. Understanding of the fundamental mechanisms1-3 as well as the limitations to optical devices4,5 is still being considered actively. This paper reports the results of our studies of the nonlinear optics of excitons confined to zero dimension and examines its manifestation on the phenomena of dynamic Stark effect, optical phase conjugation, and two-beam coupling.